Study says if you're driving an electric car on the East Coast, you're probably polluting more than your gas-guzzling neighbor

Tesla Motors CEO Elon Musk probably doesn't want to hear this.
REUTERS/Rebecca Cook
One of the main selling points of electric cars is the Captain Planet appeal you get when driving down the highway, trailing absolutely zero pollutants behind you. But a new study by a team of economists suggests this moral satisfaction might be misguided — at least if you live on the East Coast.

The researchers used county-level measurements of total pollution to compare electric cars to gas ones, and observed which are actually better for the environment. Electric cars still have to get their energy from somewhere — they need to be charged after all — and the thesis was there would be variation in how "green" an electric car was depending on how a county produced electricity.

The team found that not only were there major differences in how environmentally-friendly a car was from county to county, but also from coast to coast.

"It just turns out the West is a lot cleaner than the East," co-author Stephen Holland told CityLab. And if you look at the maps below, it's startling. The map on the left shows the polluting power of a gas car, while the right shows an electric one. The scale goes from green (good) to red (bad), and the economic damages range from approximately 1 to 5 cents per mile on each side.

In the gas car graph, there isn't too much geographical variation except in densely populated urban areas, like New York City (red), which makes sense given the pollution has less of an opportunity to disperse. Conversely, the electric car graph shows an intense geographical variation between East and West coast, with the South being somewhere in the (orange) middle.

This is because in the Midwest and Northeast, electricity tends to come from dirty coal power plants, which isn't always the case in the West.

Some of the county-level differences are telling as well. "Gasoline vehicle damages are large in Los Angeles (due to the large population and properties of the airshed) but electric vehicle damages are small (due to the clean Western power grid)," the study said.

Of course, there are caveats to the research. The researchers compared the emissions of gas cars to those produced by electricity grids. This means if you are running your electric car from a solar panel, you're still much greener than your neighbor with the gas guzzler.